Dell 210-AXLE User Manual

Dell S2421H/S2721H Monitor

User’s Guide

Model: S2421H/S2721H
Regulatory model: S2421Ht/S2721Ht

NOTE: A NOTE indicates important information that helps you make
better use of your monitor.

CAUTION: A CAUTION indicates potential damage to hardware or loss of
data if instructions are not followed.

WARNING: A WARNING indicates a potential for property damage,
personal injury, or death.

Copyright © 2020 Dell Inc. or its subsidiaries. All rights reserved. Dell, EMC, and other trademarks are

trademarks of Dell Inc. or its subsidiaries. Other trademarks may be trademarks of their respective owners.

2020 – 07

Rev. A00

Contents

Safety instructions.......................... 5

About your monitor ......................... 6

Package contents . . . . . . . . . . . . . . . . . . . . . . 6

Product features . . . . . . . . . . . . . . . . . . . . . . .7

Identifying parts and controls . . . . . . . . . . . . . . . .8

Front view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Back view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Bottom view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Monitor specifications . . . . . . . . . . . . . . . . . . . 11

Resolution specifications . . . . . . . . . . . . . . . . . . . . . . 12

Preset display modes . . . . . . . . . . . . . . . . . . . . . . . . 12

Electrical specifications. . . . . . . . . . . . . . . . . . . . . . . 13

Speaker specifications . . . . . . . . . . . . . . . . . . . . . . . 13

Physical characteristics. . . . . . . . . . . . . . . . . . . . . . . 13

Environmental characteristics . . . . . . . . . . . . . . . . . . . 14

Power management modes . . . . . . . . . . . . . . . . . . . . . 15

Pin assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Plug-and-play . . . . . . . . . . . . . . . . . . . . . . . 18

LCD monitor quality and pixel policy . . . . . . . . . . . 18

Ergonomics. . . . . . . . . . . . . . . . . . . . . . . . . 18

Handling and moving your display. . . . . . . . . . . . . 20

Maintenance guidelines . . . . . . . . . . . . . . . . . . 21

Cleaning your monitor. . . . . . . . . . . . . . . . . . . . . . . . 21

Contents | 3

Setting up the monitor...................... 22

Connecting the stand . . . . . . . . . . . . . . . . . . . 22

Using the tilt . . . . . . . . . . . . . . . . . . . . . . . . 25

Connecting your monitor . . . . . . . . . . . . . . . . . 26

Organizing your cables . . . . . . . . . . . . . . . . . . 27

Securing your monitor using Kensington lock (optional) . 27

Removing the monitor stand . . . . . . . . . . . . . . . 28

Wall mounting (Optional) . . . . . . . . . . . . . . . . . 29

Operating the monitor ...................... 30

Power on the monitor . . . . . . . . . . . . . . . . . . . 30

Using the front panel controls. . . . . . . . . . . . . . . 30

Using the OSD lock function . . . . . . . . . . . . . . . 32

Front-panel button. . . . . . . . . . . . . . . . . . . . . 35

Using the On-Screen Display (OSD) menu . . . . . . . . 36

Accessing the menu system . . . . . . . . . . . . . . . . . . . . 36

OSD warning messages . . . . . . . . . . . . . . . . . . . . . . .46

Setting the maximum resolution . . . . . . . . . . . . . . . . . . 48

Troubleshooting ........................... 49

Self-test . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Built-in diagnostics . . . . . . . . . . . . . . . . . . . . 50

Common problems . . . . . . . . . . . . . . . . . . . . . 51

Product specific problems. . . . . . . . . . . . . . . . . 53

Appendix................................. 54

FCC notices (U.S. only) and other regulatory information 54

Contacting Dell. . . . . . . . . . . . . . . . . . . . . . . 54

Outline dimension ......................... 55

4 | Contents

Safety instructions

CAUTION: Use of controls, adjustments, or procedures other than those

specified in this documentation may result in exposure to shock, electrical
hazards, and/or mechanical hazards.

• Place the monitor on a solid surface and handle it carefully. The screen is fragile
and can be damaged if dropped or hit sharply.

• Always be sure that your monitor is electrically rated to operate with the AC
power available in your location.

• Keep the monitor in room temperature. Excessive cold or hot conditions can have
an adverse effect on the liquid crystal of the display.

• Do not subject the monitor to severe vibration or high impact conditions. For
example, do not place the monitor inside a car trunk.

• Unplug the monitor when it is going to be left unused for an extended period of
time.

• To avoid electric shock, do not attempt to remove any cover or touch the inside
of the monitor.

For information on safety instructions, see the Safety, Environmental, and Regulatory
Information (SERI).

Safety instructions | 5

About your monitor

Package contents

Your monitor ships with the components shown below. Ensure that you have received
all the components and see Contacting Dell if anything is missing.

NOTE: Some components may be optional and may not ship with your

monitor. Somefeatures may not be available in certain countries.

Display

Stand riser

6 | About your monitor

Stand base

VESA cover

Power cable (varies by country)

HDMI cable

3

1
2
3

4

1

3

1

2

1

2

•Quick Setup Guide

•Safety, Environmental, and

Regulatory Information

3

1

5

© 2020 Dell Inc. or its subsidiaries.

2020-07

Dell S2421H/S2721H

Dell S2421H/S2721H

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© 2020 Dell Inc. or its subsidiaries.

www.dell.com/contactdell

2020-07

HDMI

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1

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HDMI

HDMI

HDMIMI

Dell.com/S2421H
Dell.com/S2721H

746.A3E01.0001
(DELL P/N: PNF73 rev.X01)

4

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Dell.com/S2421H
Dell.com/S2721H

746.A3E01.0001

(DELL P/N: PNF73 rev.X00)

www.dell.com/contactdell

Product features

The Dell S2421H/S2721H monitor has an active matrix, Thin Film Transistor (TFT),
Liquid Crystal Display (LCD), and LED backlight. The monitor features include:

• S2421H: 60.45 cm (23.8 in.) active area display (Measured diagonally) 1920 x
1080 (16:9) resolution, plus full-screen support for lower resolutions.

• S2721H: 68.6 cm (27 in.) active area display (Measured diagonally) 1920 x 1080
(16:9) resolution, plus full-screen support for lower resolutions.

• Tilt adjustment capability.

• Removable pedestal and Video Electronics Standards Association (VESA™) 100

mm mounting holes for flexible mounting solutions.

• Ultra-thin bezel minimizes the bezel gap in multi-monitor usage, enabling easier
set up with an elegant viewing experience.

• Extensive digital connectivity with HDMI helps future-proof your monitor.

• Plug and play capability if supported by your system.

• On-Screen Display (OSD) adjustments for ease of set-up and screen

optimization.

• Supports AMD FreeSync™ technology, AMD Freesync™ certified range from
48HZ -75HZ.

• Power and OSD buttons lock.

• Security lock slot.

• 0.3 W standby power when in the standby mode.

• Optimize eye comfort with a flicker-free screen.

WARNING: The possible long-term effects of blue light emission from the

monitor may cause damage to the eyes, including eye fatigue or digital eye
strain. ComfortView feature is designed to reduce the amount of blue light

emitted from the monitor to optimize eye comfort.

About your monitor | 7

Identifying parts and controls

Front view

1 2

Label Description Use
1 Function buttons For more information, see Operating the Monitor
2 Power on/off button

(with LED indicator)

To turn the monitor on or off.

8 | About your monitor

Back view

1
2

3
4

DELL S2421HN

Flat Panel Monitor / 液晶显示器
型号 : S2421HN

Input Rating / 输入电源 :
100-240V ~ 50/60Hz 1.5A
Made in China / 制造地:中国
Manufactured date / 制造日期:

DELL S2421HN

Flat Panel Monitor / Monitor Plano Panel / Monite ur à écran plat / 液晶顯 示器
Model No. / N° de Modelo / Numéro de modèle /型號: S2421Ht
Input Rating / Entrada / Daya Tegangan / Tension d’entrée : 100-240V ~ 50/60Hz 1.5A
輸入電源:交流電壓 100-240伏特, 1.5安培, 50/60赫茲

Made in China / Fabricado en China / Fabriqué en Chine / Сделано в Китае / 製造地:中國
Consumo de energía en operación: XX.XX Wh

2

Удельная мощность рабочего режима -X,XXX Вт/см

Потребляемая мощность изделием в режиме ожидания -X,XX Вт
Потребляемая мощность изделием в выключенном режиме - X,XX Вт

Apparatet må tilkoples jordet stikkontakt.
Apparaten skall anslutas till jordat uttag.
Apparatets stikprop skal tilsluttes en stikkontakt med jord,
som giver forbindelse til stikproppens jord.
Laite on liitettävä suojakoskettimilla varustettuun pistorasiaan.

신청인: Wistron Corporation (For Korea)
Wistron InfoComm (Zhongshan) Corporation Linhai Branch
제조자: Wistron InfoComm (Zhongshan) Corporation Linhai Branch

A/S 연락처: 080-854-0066
제조국: 중국

CAN ICES-3 (B)/NMB-3(B)

警語:使用過度恐傷害視力

For UK only: Cain Road, Bracknell, RG12 1LF
This device complies with part 15 of the FCC Rules.

XXXXXXXXXX

ID

Operation is subject to the following two conditions:
(1) this device may not cause harmful interference, and
(2) this device must accept any interference received,

XXXXXXXX-XXXXX

including interference that may cause undesired operation.

R-R-WT1-S2421Ht

E

t

IS 13252 (Part 1)/

IEC 60950-1

XXXXXX-XX

R-41071650

www.bis.gov.in

ID XXXXXXXXXX

Address for EU Only:
Raheen Business Park
Limerick Ireland
www.dell.com/regulatory_compliance

И005-20

XXXXX

Flat Panel Monitor / 液晶显示器

DELL S2421HN

型号 : S2421HN

Input Rating / 输入电源 :
100-240V ~ 50/60Hz 1.5A
Made in China / 制造地:中国

E

Manufactured date / 制造日期:

t

Label Description Use
1 VESA mounting holes (100 mm x

100 mm-behind attached VESA
cover)

Wall mount monitor using VESA­compatible wall mount kit (100 mm x
100 mm).

2 Regulatory label Lists the regulatory approvals.
3 Stand release button Releases stand from monitor.
4 Barcode, serial number, and Service

Tag label

Refer to this label if you need to contact
Dell for technical support. The Service
Tag is a unique alphanumeric identifier
that enables Dell service technicians
to identify the hardware components
in your display and access warranty
information.

5 Cable management slot Use to organize cables by placing them

through the slot.

5

About your monitor | 9

Bottom view

32 4 5 6

71

Label Description Use
1 Built-in right speaker Provides audio output.
2 Security lock slot Secures monitor with security cable lock

(sold separately).

3 Power connector Connect the power cable (shipped with your

monitor).

4 HDMI port 1 Connect your computer with HDMI cable.
5 HDMI port 2 Connect your computer with HDMI cable.
6 Audio line-out port Connect speakers to playback audio through

HDMI audio channel.

Only two-channel audio is supported.

NOTE: The audio line-out port does not support
headphones.

7 Built-in left speaker Provides audio output.

10 | About your monitor

Monitor specifications

Model S2421H S2721H

Screen type Active matrix - TFT LCD
Panel Type In-plane switching Technology
Aspect ratio 16:9
Viewable image dimensions
Diagonal 60.45 cm (23.8 in.) 68.6 cm (27 in.)
Active Area
Horizontal 527.04 mm (20.75 in.) 597.89 mm (23.54 in.)
Vertical 296.46 mm (11.67 in.) 336.31 mm (13.24 in.)

2

Area 156246.28 mm
Pixel pitch 0.2745 mm x 0.2745 mm 0.3114 mm x 0.3114 mm
Pixel per inch (PPI) 92.56 81.59
Viewing angle
Horizontal 178° (typical)
Vertical 178° (typical)
Brightness 250 cd/m² (typical) 300 cd/m² (typical)
Contrast ratio 1000 to 1 (typical)
Display screen coating Anti-glare treatment of the front polarizer (3H) hard coating
Backlight LED edgelight system
Response Time (Gray

to Gray)

8 ms (normal)

5 ms (fast)

4 ms (extreme)
Color depth 16.7 million colors
Color gamut* NTSC 72%
Connectivity •2 x HDMI1.4

•1 x Audio line out (3.5 mm jack)

Border width (edge of monitor to active area)
Top/Left/Right 5.4 mm 6.0 mm
Bottom 20.7 mm 21.3 mm
Adjustability
Height adjustable

NA
stand

Tilt -5° to 21°

Swivel NA
Pivot NA

(242.15 in.2) 201073.02 mm2 (311.67 in.2)

About your monitor | 11

Cable management Yes

(Hz)

VESA, 1280 x 1024

80.0

75.0

135.0

+/+

Dell Display Manager
(DDM)Compatibility

Security Security lock slot (cable lock sold separately)

* At panel native resolution only, under Custom Mode preset.

Resolution specifications

Model S2421H/S2721H

Horizontal scan range 30 kHz to 83 kHz
Vertical scan range 48 Hz to 75 Hz
Maximum preset resolution 1920 x 1080 at 60 Hz
Video display capabilities

(HDMI playback)

Preset display modes

S2421H/S2721H

Easy Arrange and other key features

480i, 480p, 576i, 576p, 720p, 1080i, 1080p

Display Mode Horizontal

Frequency
(kHz)

VGA, 720 x 400 31.5 70.0 28.3 - /+
VGA, 640 x 480 31.5 60.0 25.2 -/­VESA, 640 x 480 37.5 75.0 31.5 -/­VESA, 800 x 600 37.9 60.0 40.0 +/+
VESA, 800 x 600 46.9 75.0 49.5 +/+
VESA, 1024 x 768 48.4 60.0 65.0 - /­VESA, 1024 x 768 60.0 75.0 78.8 +/+
MAC, 1152 x 864 6 7.5 75.0 108.0 +/+
VESA, 1280 x 1024 64.0 60.0 108.0 +/+

VESA, 1600 x 900 60.0 60.0 108.0 +/+
CVT, 1920 x 1080 67.5 60.0 148.5 +/+
CVT, 1920 x 1080 83.89 75.0 174.5 +/-

Vertical
Frequency

Pixel Clock
(MHz)

Sync Polarity
(Horizontal/
Vertical)

12 | About your monitor

Electrical specifications

Model S2421H/S2721H

Video input signals •Digital video signal for each dierential line

Per dierential line at 100 ohm impedance

•HDMI signal input support

Input voltage/ frequency/
current

Inrush current 120 V: 30 A (maximum)

Speaker specifications

Model S2421H/S2721H

Speaker rated power 2 x 3W
Frequency response 315 Hz - 12.5 kHz
Impedance 4 ohm

Physical characteristics

100-240 VAC / 50 or 60 Hz ± 3 Hz / 1.5 A
(maximum)

240 V: 60 A (maximum)

Model

Connector type •2 x HDMI1.4 ports

Signal cable type 1.8 m HDMI1.4 cable
Dimensions (with stand)
Height

Width

Depth

Dimensions (without stand)

Height

Width

Depth

Stand dimensions

Height

Width

Depth

S2421H S2721H

•1 x Audio line-out port

412.8 mm (16.25 in.) 453.3 mm (17.85 in.)

537.8 mm (21.17 in.) 609.9 mm (24.01 in.)

152.8 mm (6.02 in.) 186.8 mm (7.35 in.)

322.6 mm (12.70 in.) 363.6 mm (14.32 in.)

537.8 mm (21.17 in.) 609.9 mm (24.01 in.)

53.8 mm (2.12 in.) 54.0 mm (2.13 in.)

171.6 mm (6.76 in.) 176.0 mm (6.93 in.)

249.0 mm (9.80 in.) 257.2 mm (10.13 in.)

152.8 mm (6.02 in.) 186.8 mm (7.35 in.)

About your monitor | 13

Weight
Weight with packaging 6.0 kg (13.23 lb.) 7.7 kg (16.98 lb.)
Weight with stand assembly

and cables
Weight without stand

assembly (For wall mount or
VESA mount considerations

- no cables)
Weight of stand assembly 0.5 kg (1.1 lb.) 0.7 kg (1.54 lb.)

Environmental characteristics

Model S2421H/S2721H

Compliant Standards

•ENERGY STAR certied Monitor.

•TCO Certied Display.

•RoHS Compliant.

•BFR/PVC Reduce monitor (excluding external cables).

•Arsenic-Free glass and Mercury-Free for the panel only.

Temperature
Operating 0°C to 40°C (32°F to 104°F)
Non-operating –20°C to 60°C (–4°F to 140°F)
Humidity
Operating 10% to 80% (non-condensing)
Non-operating 5% to 90% (non-condensing)

Altitude
Operating (maximum) 5,000 m (16,404 ft)
Non-operating (maximum) 12,192 m (40,000 ft)
Thermal dissipation

S2421H 102.36 BTU/hour (maximum)

S2721H 139.90 BTU/hour (maximum)

4.2 kg (9.26 lb.) 5.4 kg (11.9 lb.)

3.4 kg (7.5 lb.) 4.4 kg (9.7 lb.)

68.24 BTU/hour (typical)

71.65 BTU/hour (typical)

14 | About your monitor

Power management modes

If you have VESA’s DPM-compliant video card or software installed in your PC, the
monitor can automatically reduce its power consumption when not in use. This is
referred to as standby mode*. If the computer detects input from the keyboard,
mouse, or other input devices, the monitor automatically resumes functioning. The
following table shows the power consumption and signaling of this automatic power
saving feature.

S2421H

VESA
Modes

Normal

Horizontal
Sync

Vertical
Sync

Video Power Indicator Power

Active Active Active White 30 W (maximum)**

operation
Active-

Inactive Inactive Off White

off mode

Switch

- - - Off Less than 0.3 W

off

Power Consumption P

on

11.81 W

Total Energy Consumption (TEC) 37.52 kWh

S2721H

VESA
Modes

Normal

Horizontal
Sync

Vertical
Sync

Video Power Indicator Power

Active Active Active White 41 W (maximum)**

operation
Active-

Inactive Inactive Off White

off mode

Switch

- - - Off Less than 0.3 W

off

Power Consumption P

on

14.64 W

Total Energy Consumption (TEC) 46.14 kWh

Consumption

20 W (typical)
Less than 0.3 W

(Glowing)

Consumption

21 W (typical)
Less than 0.3 W

(Glowing)

About your monitor | 15

The OSD operates only in the normal operation mode. If you press any button in the
active-off mode, the following message is displayed:

Dell 24/27 Monitor

No HDMI1 signal from your device.

Press any key on the keyboard or move the mouse to wake it up.

If there is no display, press the monitor button again to select

the correct input source.

S2421H/S2721H

*Zero power consumption in OFF mode can only be achieved by disconnecting the AC

mains cable from the monitor.

**Maximum power consumption with maximum luminance.

This document is informational only and reflects laboratory performance. Your product
may perform differently, depending on the software, components and peripherals
you ordered and shall have no obligation to update such information. Accordingly, the
customer should not rely upon this information in making decisions about electrical
tolerances or otherwise. No warranty as to accuracy or completeness is expressed or
implied.

Activate the computer and the monitor to gain access to the OSD.

NOTE: This monitor is ENERGY STAR certified.

This product qualifies for ENERGY STAR in the factory default settings which can
be restored by “Factory Reset” function in the OSD menu. Changing the factory
default settings or enabling other features may increase power consumption that
could exceed the ENERGY STAR specified limit.

NOTE:

Pon: Power consumption of On Mode as defined in Energy Star 8.0 version.

TEC: Total energy consumption in kWh as defined in Energy Star 8.0 version.

16 | About your monitor

Pin assignments

HDMI port

Pin number 19-pin side of theconnected signal cable

1 TMDS DATA 2+

2 TMDS DATA 2 SHIELD

3 TMDS DATA 2-

4 TMDS DATA 1+

5 TMDS DATA 1 SHIELD

6 TMDS DATA 1-

7 TMDS DATA 0+

8 TMDS DATA 0 SHIELD

9 TMDS DATA 0-

10 TMDS CLOCK+

11 TMDS CLOCK SHIELD

12 TMDS CLOCK-

13 CEC

14 Reserved (N.C. on device)

15 DDC CLOCK (SCL)

16 DDC DATA (SDA)

17 DDC/CEC Ground

18 +5 V POWER

19 HOT PLUG DETECT

About your monitor | 17

Plug-and-play

You can install the monitor in any Plug-and-Play-compatible system. The monitor
automatically provides the computer system with its extended display identification
data (EDID) using display data channel (DDC) protocols so the computer can configure
itself and optimize the monitor settings. Most monitor installations are automatic;
you can select different settings if desired. For more information about changing the
monitor settings, see Operating the Monitor.

LCD monitor quality and pixel policy

During the LCD monitor manufacturing process, it is not uncommon for one or more
pixels to become fixed in an unchanging state which are hard to see and do not affect
the display quality or usability. For more information on LCD Monitor Pixel Policy, see
Dell support site at: https://www.dell.com/pixelguidelines.

Ergonomics

CAUTION: Improper or prolonged usage of keyboard may result in injury.

CAUTION: Viewing the monitor screen for extended periods of time may

result in eye strain.

For comfort and efficiency, observe the following guidelines when setting up and using
your computer workstation:

• Position your computer so that the monitor and keyboard are directly in front of
you as you work. Special shelves are commercially available to help you correctly
position your keyboard.

• To reduce the risk of eye strain and neck/arm/back/shoulder pain from using the
monitor for long periods of time, we suggest you to:

1. Set the distance of the screen between 20 to 28 in. (50 - 70 cm) from your
eyes.

2. Blink frequently to moisten your eyes or wet your eyes with water after
prolonged usage of the monitor.

3. Take regular and frequent breaks for 20 minutes every two ho

4. Look away from your monitor and gaze at a distant object at 20 feet away for
at least 20 seconds during the breaks.

5. Perform stretches to relieve tension in the neck, arm, back, and shoulders
during the breaks.

• Make sure that the monitor screen is at eye level or slightly lower when you are
sitting in front of the monitor.

• Adjust the tilt of the monitor, its contrast, and brightness settings.

18 | About your monitor

• Adjust the ambient lighting around you (such as overhead lights, desk lamps, and
the curtains or blinds on nearby windows) to minimize reflections and glare on the
monitor screen.

• Use a chair that provides good lower-back support.

• Keep your forearms horizontal with your wrists in a neutral, comfortable position

while using the keyboard or mouse.

• Always leave space to rest your hands while using the keyboard or mouse.

• Let your upper arms rest naturally on both sides.

• Ensure that your feet are resting flat on the floor.

• When sitting, make sure that the weight of your legs is on your feet and not

on the front portion of your seat. Adjust your chair’s height or use a footrest if
necessary to maintain a proper posture.

• Vary your work activities. Try to organize your work so that you do not have to sit
and work for extended periods of time. Try to stand or get up and walk around at
regular intervals.

• Keep the area under your desk clear of obstructions and cables or power cords
that may interfere with comfortable seating or present a potential trip hazard.

monitor screen at or
below eye level

wrists relaxed
and at

monitor and
keyboard
positioned
directly in front
of the user

feet at on the
oor

About your monitor | 19

Handling and moving your display

To ensure the monitor is handled safely when lifting or moving it, follow the guidelines
mentioned below:

• Before moving or lifting the monitor, turn off your computer and the monitor.

• Disconnect all cables from the monitor.

• Place the monitor in the original box with the original packing materials.

• Hold the bottom edge and the side of the monitor firmly without applying

excessive pressure when lifting or moving the monitor.

• When lifting or moving the monitor, ensure the screen is facing away from you
and do not press on the display area to avoid any scratches or damage.

• When transporting the monitor, avoid any sudden shock or vibration to it.

20 | About your monitor

• When lifting or moving the monitor, do not turn the monitor upside down while
holding the stand base or stand riser. This may result in accidental damage to the
monitor or cause personal injury.

Maintenance guidelines

Cleaning your monitor

CAUTION: Read and follow the Safety instructions before cleaning the

monitor.

WARNING: Before cleaning the monitor, unplug the monitor power cable

from the electrical outlet.

For best practices, follow the instructions in the list below when unpacking, cleaning,
or handling your monitor:

• To clean your anti-static screen, lightly dampen a soft, clean cloth with water. If
possible, use a special screen-cleaning tissue or solution suitable for the anti­static coating. Do not use benzene, thinner, ammonia, abrasive cleaners, or
compressed air.

• Use a lightly-dampened, warm cloth to clean the monitor. Avoid using detergent
of any kind as some detergents leave a milky film on the monitor.

• If you notice white powder when you unpack your monitor, wipe it off with a
cloth.

• Handle your monitor with care as a darker-colored monitor may get scratched
and show white scuff marks more than a lighter-colored monitor.

• To help maintain the best image quality on your monitor, use a dynamically
changing screen saver and turn off your monitor when not in use.

About your monitor | 21

Setting up the monitor

Connecting the stand

NOTE: The stand riser and stand base are detached when the monitor is

shipped from the factory.

NOTE: The following instructions are applicable only for the stand that

was shipped with your monitor. If you are connecting a stand that you
purchased from any other source, follow the set up instructions that were
included with the stand.

CAUTION: Place monitor of a flat, clean, and soft surface to avoid

scratching the display panel.

To attach the monitor stand:

1. Align the tabs on the stand base with the slots on the stand riser.

2. Insert the stand riser on the stand base rmly.

3. Open the screw handle at the bottom of the stand base, and rotate it clockwise
to tighten the screw rmly. Then close the screw handle.

1

2

3

22 | Setting up the monitor

4. Open the monitor protective cover, install the VESA screw cover.

5. Align the tabs on the stand-riser bracket with the grooves at the back of the
monitor.

6. Insert the stand-riser bracket into monitor groove until it snaps into its place.

5

6

Setting up the monitor | 23

CAUTION: Hold the stand riser firmly when lifting the monitor to avoid

any accidental damage.

7. Hold the stand riser and lift the monitor carefully, then place it on a at surface.

8. Lift the protective cover from the monitor.

24 | Setting up the monitor

Using the tilt

NOTE: The following instructions are applicable only for the stand that

was shipped with your monitor. If you are connecting a stand that you
purchased from any other source, follow the set up instructions that were
included with the stand.

With the stand attached to the monitor, you can tilt the monitor for the most
comfortable viewing angle.

°

5

°

21

NOTE: The stand is detached when the monitor is shipped from the

factory.

Setting up the monitor | 25

Connecting your monitor

WARNING: Before you begin any of the procedures in this section, follow

the Safety Instructions.

To connect your monitor to the computer:

1. Turn o your computer.

2. Connect the HDMI cable from your monitor to thecomputer.

3. Turn on your monitor.

4. Select the correct input source from the OSD Menu on your monitor and then

turn on your computer.

Connecting the HDMI cable

HDMI

HDMI

26 | Setting up the monitor

Organizing your cables

HDMI

After connecting all necessary cables to your monitor and computer, (see Connecting

Your Monitor for cable attachment) organize all cables as shown above.

Securing your monitor using Kensington lock (optional)

The security lock slot is located at the bottom of the monitor. (See Security lock slot)

For more information on using the Kensington lock (purchased separately), see the
documentation that is shipped with the lock.

Secure your monitor to a table using the Kensington security lock.

NOTE: The image is for the purpose of illustration only. Appearance of the

lock may vary.

Setting up the monitor | 27

Removing the monitor stand

CAUTION: To prevent scratches on the LCD screen while removing the

stand,make sure that the monitor is placed on a soft, clean surface.

NOTE: The following instructions are applicable only for the stand that

was shipped with your monitor. If you are connecting a stand that you
purchased from any other source, follow the set up instructions that were
included with the stand.

To remove the stand:

1. Place a at cushion or a sitting mat near the edge of a table and place the
monitor on it with the display facing down.

2. Press the stand down to access to the release latch.

3. Use a long screwdriver to press the release latch.

4. While pressing the release latch, slide out the stand assembly from the monitor.

3

4

To remove the VESA cover:

Press the dimple on the VESA cover to release it from the back of the display.

28 | Setting up the monitor

Wall mounting (Optional)

DELL S2421H

Flat Panel Monitor / Monitor Plano Pa nel / Monit eur à écran plat / 液晶顯 示器
Model No. / N° de Modelo / Numéro de modèle /型號: S2 421Ht
Input Rating / Entrada / Daya Tegangan / Tension d’entré e: 100-240V ~ 50/60Hz 1 .5A
輸入電源: 交流電壓 100-240伏特, 1.5安培, 50/60赫茲

Made in China / Fabricado en China / Fabriqué en Chine / Сделано в Китае / 製造地:中國
Consumo de energía en operación: XX.XX Wh

2

Удельная мощность рабочего режима -X,XXX Вт/см
Потребляемая мощность изделием в режиме ожидания -X,XX Вт
Потребляемая мощность изделием в выключенном режиме - X,XX Вт

Apparatet må tilkoples jordet stikkontakt.
Apparaten skall anslutas till jordat uttag.
Apparatets stikprop skal tilsluttes en stikkontakt med jord,
som giver forbindelse til stikproppens jord.
Laite on liitettävä suojakoskettimilla varustettuun pistorasiaan.
신청인: Wistron Corporation (For Korea)
Wistron InfoComm (Zhongshan) Corporation Linhai Branch
제조자: Wistron InfoComm (Zhongshan) Corporation Linhai Branch

A/S 연락처: 080-854-0066
제조국: 중국

CAN ICES-3 (B)/NMB-3(B)
For UK only: Cain Road, Bracknell, RG12 1LF
This device complies with part 15 of the FCC Rules.
Operation is subject to the following two conditions:
(1) this device may not cause harmful interference, and
(2) this device must accept any interference received,
including interference that may cause undesired operation.

DELL S2421H

Flat Panel Monitor / 液晶显示器
型号 : S2421H
Input Rating / 输入电源 :

E

100-240V ~ 50/60Hz 1.5A
Made in China / 制造地:中国
Manufactured date / 制造日期:

NOTE: Use M4 x 10 mm screws to secure the wall-mounting kit to the

monitor.

See the documentation that is shipped with the VESA-compatible wall mounting kit.

1. Place a at cushion or a sitting mat near the edge of a table and place the
monitor on it with the display facing down.

2. Remove the stand.

3. Using a Phillips crosshead screwdriver, remove the four screws that secure the
back panel.

4. Connect the mounting bracket from the wall mounting kit to the monitor.

5. Follow the instructions that shipped with the wall-mounting kit and mount the
monitor on the wall.

NOTE: For use only with UL or CSA or GS-listed wall mount bracket

with minimum weight/load bearing capacity of 13.8 kg (S2421H)/17.6 kg
(S2721H).

IS 13252 (Part 1)/

IEC 60950-1

XXXXXX-XX

警語: 使用過度恐傷害視力

R-41071650

ID

XXXXXXXXXX

www.bis.gov.in

ID XXXXXXXXXX

Address for EU Only:
Raheen Business Park
Limerick Ireland
www.dell.com/regulatory_compliance

XXXXXXXX-XXXXX

R-R-WT1-S2421Ht

И005-20

XXXXX

t

Setting up the monitor | 29

Operating the monitor

Power on the monitor

Press the button to turn on the monitor.

Using the front panel controls

Use the control buttons at the bottom edge of the monitor to adjust the specifications
of the image being displayed. When using the control buttons, an On-Screen Display
(OSD) menu appears on the screen with numeric values.

30 | Operating the monitor

1 2 3 4 5

The following table describes the front panel buttons:

Front-Panel Button Description
1

Shortcut key:

Preset Modes

2

Shortcut key:

Volume

3

Menu

4

Exit

5

Power (with power light

indicator)

Use this button to choose from a list of preset
colormodes.

Use this button to adjust the volume of the built-in
speakers.

Use this menu button to launch the on-screen
display (OSD) and select the OSD menu.

See Accessing the Menu System.

Use this button to go back to the main menu or exit
the OSD main menu.

Use the Power button to turn the monitor On and
Off.

The white LED indicates the monitor is On and fully
functional.

A Breathing white LED indicates DPMS Standby
Mode.

Operating the monitor | 31

Using the OSD lock function

You can lock the front-panel control buttons to prevent access to the OSD menu and/
or power button.

Use the Lock menu to lock the button(s).

1. Select one of the following options.

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Audio

Menu

Personalize

Others

2. The following message appears.

Dell 24/27 Monitor

Are you sure you want to lock the Menu Buttons?

To unlock the Buttons, refer to the User’s Guide.

Language

Transparency

Timer

Lock

Reset Menu

Menu Buttons

Power Button

Menu + Power Buttons

Disable

Yes No

S2421H/S2721H

3. Select Yes to lock the buttons. Once locked, pressing any control button will

display the lock icon

32 | Operating the monitor

Use the front-panel control button to lock the button(s).

1 2 3 4 5

1. Press and hold Button 4 for four seconds, a menu appears on the screen.

Dell 24/27 Monitor

Select Option:

2. Select one of the following options:

Options Description
1

Select this option to lock OSD menu function.

Menu Buttons lock

2

Power Button lock

3

Menu and Power Buttons

lock

4

Built-in Diagnostics

Use this option to lock power button. This will
prevent the user to turn off the monitor using the
power button.

Use this option to lock OSD menu and power
button to turn off the monitor.

Use this option to run the built-in diagnostics, see

Built-in Diagnostics.

Operating the monitor | 33

To unlock the button(s).

Press and hold Button 4 for four seconds until a menu appears on the screen. The
following table describes the options to unlock the front-panel control buttons.

Dell 24/27 Monitor

Select Option:

Dell 24/27 Monitor

Select Option:

Options Description

1

Use this option to unlock OSD menu function.

Menu Buttons unlock

2

Use this option to unlock power button to turn off
the monitor.

Power Button unlock

3

Use this option to unlock OSD menu and power
button to turn off the monitor.

Menu and Power Buttons

unlock

4

Use this option to run the built-in diagnostics, see

Built-in Diagnostics.

Dell 24/27 Monitor

Select Option:

Built-in Diagnostics

34 | Operating the monitor

Front-panel button

Use the buttons on the front of the monitor to adjust the image settings.

2 31

Front Panel Button Description

1

Up Down

2

3

OK

Use the Up (increase) and Down (decrease) buttons to
adjust items in the OSD menu.

Use the OK button to confirm your selection.

Use the Back button to go back to the previous menu.

Back

Operating the monitor | 35

Using the On-Screen Display (OSD) menu

Accessing the menu system

NOTE: The changes you make using the OSD menu are automatically saved

when youmove to another OSD menu, when you exit the OSD menu, or
when the OSD menu todisappears automatically.

1. Press the

button to launch the OSD menu and display the main menu.

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Audio

Menu

Personalize

Others

75%

75%

2. Press the and buttons to move between options. As you move from one icon
to another, the option name is highlighted.

3. Press the

4. Press the

5. Press
indicators on the menu, to make your changes.

6. Select the
menu.

or or button once to activate the highlighted option.

and buttons to select the desired parameter.

to enter the slide bar and then use the or button, according to the

to return to previous menu or to accept and return to previous

36 | Operating the monitor

Icon Menu and

Description

Submenus

Brightness/
Contrast

Use this menu to activate Brightness/Contrast adjustment.

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Audio

Menu

Personalize

Others

Brightness Brightness adjusts the luminance of the backlight

(minimum 0; maximum 100).

Press the

Press the

button to increase brightness.

button to decrease brightness.

Contrast Adjust the Brightness first, and then adjust Contrast only if

further adjustment is necessary.

Press the

button to increase contrast and press the

button to decrease contrast (between 0 and 100).

Contrast adjusts the difference between darkness and
lightness on the monitor.

Input Source Use the Input Source menu to select between different

video inputs that are connected to your monitor.

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Audio

Menu

Personalize

Others

HDMI1

HDMI2

Auto select

Reset Input Source

On

75%

75%

Operating the monitor | 37

Icon Menu and

Description

Submenus

HDMI 1 Select HDMI1 input when you are using the HDMI1

connector.

Use

to select the HDMI input source.

HDMI 2 Select HDMI2 input when you are using the HDMI2

connector.

Auto Select

Use

Use

to select the HDMI input source.

to select Auto Select, the monitor scans for available

input sources.

Reset Input
Source

Resets your monitor’s Input Source settings to the factory
defaults.

Color Use the Color menu to adjust the color setting mode.

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Audio

Menu

Personalize

Others

Preset Modes

Input Color Format

Reset Color

Standard

RGB

38 | Operating the monitor

Icon Menu and

Submenus

Preset
Modes

Description

When you select Preset Modes, you can choose Standard,
ComfortView, Movie, FPS, RTS, RPG, Warm, Cool or
Custom Color from the list.

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Audio

Menu

Personalize

Others

Preset Modes

Input Color Format

Reset Color

Standard

ComfortView

Movie

FPS

RTS

RPG

Warm

Cool

Custom Color

•Standard: Default color settings. This is the default preset
mode.

•ComfortView: Decreases the level of blue light emitted
from the screen to make viewing more comfortable for your
eyes.

WARNING: The possible long-term effects of blue light
emission from the monitor may cause personal injury
such as digital eye strain, eye fatigue and damage to
the eyes. Using monitor for extended periods of time
may also cause pain in parts of body such as neck,
arm, back and shoulder. For more information, see

Ergonomics.

•Movie: Loads color settings ideal for movies.

•FPS: Loads color settings ideal for First-Person Shooter

games.

•RTS: Loads color settings ideal for Real-Time Strategy
games.

•RPG: Loads color settings ideal for Role-Playing games.

Operating the monitor | 39

Icon Menu and

Submenus

Input Color
Format

Description

•Warm: Increases the color temperature. The screen appears
warmer with a red/yellow tint.

•Cool: Decreases the color temperature. The screen appears
cooler with a blue tint.

•Custom Color: Allows you to manually adjust the color
settings. Press the

and buttons to adjust the Red,
Green, and Blue values and create your own preset color
mode.

Allows you to set the video input mode to:

•RGB: Select this option if your monitor is connected to a
computer (or DVD player) using the HDMI cable.

•YPbPr: Select this option if your DVD player supports only
YPbPr output.

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Audio

Menu

Personalize

Others

Preset Modes

Input Color Format

Reset Color

RGB

YPbPr

Hue

Use

or to adjust the hue from 0 to 100.

NOTE: Hue adjustment is available only for Movie and FPS,
RTS, RPG mode.

Saturation

Use

or to adjust the saturation from 0 to 100.

NOTE: Saturation adjustment is available only for Movie and
FPS, RTS, RPG mode.

Reset Color Resets your monitor’s color settings to the factory defaults.

40 | Operating the monitor

Icon Menu and

Description

Submenus

Display Use the Display menu to adjust image.

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Audio

Menu

Personalize

Others

Aspect Ratio

Sharpness

Response Time

Reset Display

Wide 16:9

50

Normal

Aspect Ratio Select the image ratio between 16:9 (wide), 4:3, and 5:4.
Sharpness Makes the image look sharper or softer.

Use

or to adjust the sharpness from ‘0’ to ‘100’.

Response
Time

Allows you to set the Response Time to Normal, Fast or

Extreme.
Reset Display Restores the display settings to factory defaults.
Audio

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Audio

Menu

Personalize

Others

Volume

Speaker

Reset Audio

50

Enable

Volume Allows you to set the volume level of audio source.

Use

or to adjust the volume level from ‘0’ to ‘100’.

Speaker Allows you to enable (turn On) or disable (turn Off) the

speakers.

Reset Audio Select this option to restore default audio settings.

Operating the monitor | 41

Icon Menu and

Description

Submenus

Menu Select this option to adjust the settings of the OSD, such

as the languages of the OSD, the amount of time the menu
remains on screen, and so on.

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Audio

Menu

Personalize

Others

Transparency

Timer

Lock

Reset Menu

EnglishLanguage

20

20 s

Disable

Language Set the OSD display to one of eight languages.

(English, Spanish, French, German, Brazilian Portuguese,
Russian, Simplified Chinese, or Japanese).

Transparency Select this option to change the menu transparency by using

and (min. 0 / max. 100).

Timer OSD Hold Time: Sets the length of time the OSD remains

active after you press a button.

Use the

and buttons to adjust the slider in 1-second

increments, from 5 to 60 seconds.

42 | Operating the monitor

Icon Menu and

Description

Submenus

Lock Controls user access to adjustments. The buttons are locked.

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Audio

Menu

Personalize

Others

Language

Transparency

Timer

Lock

Reset Menu

Menu Buttons

Power Button

Menu + Power Buttons

Disable

•Menu Buttons: Through OSD to lock the Menu buttons.

•Power Button: Through OSD to lock the Power button.

•Menu + Power Buttons: Through OSD to lock the all of

Menu and Power buttons.

•Disable: Press and hold the

button next to the power

button for four seconds to unlock the buttons.

Reset Menu

Personalize

Restore the menu settings to factory defaults.

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Audio

Menu

Personalize

Others

Shortcut Key 1

Reset Personalization

Preset Modes

VolumeShortcut Key 2

On In On ModePower Button LED

Shortcut
key 1

Shortcut
key 2

Power
Button LED

Select from Preset Modes, Brightness/Contrast, Input
Source, Aspect Ratio, Volume set as shortcut key 1.

Select from Preset Modes, Brightness/Contrast, Input
Source, Aspect Ratio, Volume set as shortcut key 2.

Allows you to set the state of the power light to save energy.

Operating the monitor | 43

Icon Menu and

Description

Submenus

Reset

Restores shortcut keys to factory defaults.

Persona-

lization
Others Select this option to adjust the OSD settings suchas the

DDC/CI, LCD conditioning, and so on.

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Audio

Menu

Personalize

Others

Display Info

DDC/CI

LCD Conditioning

Firmware

Service Tag

Reset Others

Factory Reset

On

O

00X000

ABCDEF

ENERGY STAR

®

Display Info Displays the monitor’s current settings.

DDC/CI DDC/CI (Display Data Channel/Command Interface) allows

you to adjust the monitor settings using software on your
computer.

Select Off to turn off this feature.

Enable this feature for best user experience and optimum
performance of your monitor.

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Audio

Menu

Personalize

Others

Display Info

DDC/CI

LCD Conditioning

Firmware

Service Tag

Reset Others

Factory Reset

On

O

44 | Operating the monitor

Icon Menu and

Description

Submenus

LCD
Conditioning

Helps reduce minor cases of image retention. Depending on
the degree of image retention, the program may take some
time to run. Select On to start the process.

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Menu

Personalize

Others

Display Info

DDC/CI

LCD Conditioning

Firmware

Service Tag Audio

Reset Others

Factory Reset

On

O

Firmware Displays the firmware version of your monitor.

Service Tag Displays the Service Tag. The Service Tag is a unique

alphanumeric identifier that allows Dell to identify the product
specifications and access warranty information.

NOTE: The Service Tag is also printed on a label located at
the back of the cover.

Reset Others Restores other settings, such as DDC/CI, to factorydefaults.

Factory
Reset

Restores all preset values to the factory default settings.
These are also the settings for ENERGY STAR

Dell 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Audio

Menu

Personalize

Others

Display Info

DDC/CI

LCD Conditioning

Firmware

Service Tag

Reset Others

Factory Reset

On

O

00X000

ABCDEF

ENERGY STAR

®

tests.

®

Operating the monitor | 45

OSD warning messages

When the monitor does not support a particular resolution mode, you can see the
following message:

Dell 24/27 Monitor

The current input timing is not supported by the monitor display. Please

change your input timing to

listed timing as per the monitor specifications.

1920x1080, 60Hz or any other monitor

S2421H/S2721H

This means that the monitor cannot synchronize with the signal that it is receiving
from the computer. See Resolution Specifications for the Horizontal and Vertical
frequency ranges addressable by this monitor. Recommended mode is 1920 x 1080.

You can see the following message before the DDC/CI function is disabled:

Dell 24/27 Monitor

The function of adjusting display setting using PC application will be

disabled.

Do you wish to disable DDC/CI function?

Yes No

S2421H/S2721H

When the monitor enters the Standby mode, the following message appears:

Dell 24/27 Monitor

Going into Standby mode…

S2421H/S2721H

Activate the computer and wake up the monitor to gain access to the OSD.

46 | Operating the monitor

If you press any button other than the power button, the following messages will
appear depending on the selected input:

Dell 24/27 Monitor

No HDMI1 signal from your device.

Press any key on the keyboard or move the mouse to wake it up.

If there is no display, press the monitor button again to select

the correct input source.

S2421H/S2721H

If either HDMI1, HDMI2 input is selected and the corresponding cable is not connected,
a floating dialog box as shown below appears.

Dell 24/27 Monitor

No HDMI1 Cable

The display will go into Standby mode in 4 minutes.

www.dell.com/S2421H
www.dell.com/S2721H

or

S2421H/S2721H

Dell 24/27 Monitor

No HDMI2 Cable

The display will go into Standby mode in 4 minutes.

www.dell.com/S2421H
www.dell.com/S2721H

See Troubleshooting for more information.

S2421H/S2721H

Operating the monitor | 47

Setting the maximum resolution

To set the maximum resolution for the monitor:

In Windows 7, Windows 8 or Windows 8.1:

1. For Windows 8 or Windows 8.1 only, select the Desktop tile to switch to classic
desktop. For Windows Vista and Windows 7, skip this step.

2. Right-click on the desktop and click Screen Resolution.

3. Click the Dropdown list of the Screen Resolution and select 1920 x 1080.

4. Click OK.

In Windows 10:

1. Right-click on the desktop and click Display Settings.

2. Click Advanced display settings.

3. Click the dropdown list of Resolution and select 1920 x 1080.

4. Click Apply.

If you do not see the 1920 x 1080 as an option, you may need to update your graphics

driver. Depending on your computer, complete one of the following procedures:

If you have a Dell desktop or portable computer:

• Go to https://www.dell.com/support, enter your service tag, and download the
latest driver for your graphics card.

If you are using a non-Dell computer (laptop or desktop):

• Go to your computer manufacturer’s support website and download the latest
graphic drivers.

• Go to your graphics card manufacturer’s website and download the latest graphic
drivers.

48 | Operating the monitor

Troubleshooting

WARNING: Before you begin any of the procedures in this section, follow

the Safety Instructions.

Self-test

Your monitor provides a self-test feature that allows you to check whether your
monitor is functioning properly. If your monitor and computer are properly connected
but the monitor screen remains dark, run the monitor self-test by performing the
following steps:

1. Turn o both your computer and the monitor.

2. Unplug the video cable from the back of the computer. To ensure proper Self-Test
operation, remove all video cables from the back of computer.

3. Turn on the monitor.

The floating dialog box should appear on-screen (against a black background), if the
monitor cannot sense a video signal and is working correctly. While in self-test mode,
the power LED remains white. Also, depending upon the selected input, one of the
dialogs shown below will continuously scroll through the screen.

Dell 24/27 Monitor

No HDMI1 Cable

The display will go into Standby mode in 4 minutes.

www.dell.com/S2421H
www.dell.com/S2721H

S2421H/S2721H

or

Dell 24/27 Monitor

No HDMI2 Cable

The display will go into Standby mode in 4 minutes.

www.dell.com/S2421H
www.dell.com/S2721H

S2421H/S2721H

4. This box also appears during normal system operation if the video cable is
disconnected or damaged.

5. Turn o your monitor and reconnect the video cable; then turn on both your
computer and the monitor.

Troubleshooting | 49

If your monitor screen remains blank after you use the previous procedure, check your
video controller and computer, because your monitor is functioning properly.

Built-in diagnostics

Your monitor has a built-in diagnostic tool that helps you determine if the screen
abnormality you are experiencing is an inherent problem with your monitor, or with your
computer and video card.

1 2 3 4 5

To run the built-in diagnostics:

1. Ensure that the screen is clean (no dust particles on the surface of the
screen).

2. Press and hold Button 4 for four seconds, a menu appears on the screen.

3. Select the built-in diagnostics

4. Carefully inspect the screen for abnormalities.

5. Press Button 1 on the front panel again. The color of the screen changes to
red.

6. Inspect the display for any abnormalities.

7. Repeat steps 5 to 6 to inspect the display when it changes to green, blue,
black, white, and text screens.

The test is complete when the text screen appears. To exit, press Button 1 again.

If you do not detect any screen abnormalities during the built-in diagnostic tool, the
monitor is functioning properly. Check the video card and computer.

50 | Troubleshooting

option. A gray screen appears.

Common problems

The following table contains general information about common monitor problems you
might encounter and the possible solutions:

Common
Symptoms

No Video/
Power LED off

No Video/
Power LED on

Missing Pixels LCD screen has

Stuck-on Pixels LCD screen has

Brightness
Problems

Safety Related
Issues

What you
experience

No picture •Ensure that the video cable connecting the

No picture or no
brightness

spots

bright spots

Picture too dim
or too bright

Visible signs of
smoke or sparks

Possible solutions

monitor and the computer is properly connected
and secure.

•Verify that the power outlet is functioning
properly using any other electrical equipment.

•Ensure that the power button is depressed fully.

•Ensure that the correct input source is selected

in the Input Source menu.

•Increase brightness and contrast controls
through OSD.

•Perform monitor self-test feature check.

•Check for bent or broken pins in the video cable

connector.

•Run the built-in diagnostics.

•Ensure that the correct input source is selected

in the Input Source menu.

•Cyclepoweron-off.

•Pixelthatispermanentlyoffisanaturaldefect

that can occur in LCD technology.

•FormoreinformationonDellMonitorQuality

and Pixel Policy, see Dell Support site at:
www.dell.com/support/monitors.

•CyclepowerOn-Off.

•Pixelthatispermanentlyoffisanaturaldefect

that can occur in LCD technology.

•FormoreinformationonDellMonitorQuality

and PixelPolicy, see Dell Support site at:
www.dell.com/support/monitors.

•Reset the monitor to factory settings.

•Adjust brightness and contrast controls through

OSD.

•Do not perform any troubleshooting steps.

•Contact Dell immediately.

Troubleshooting | 51

Common
Symptoms

Intermittent
Problems

Missing Color Picture missing

Wrong Color Picture color

Image retention
from a static
image left on
the monitor for
a long period of
time

What you
experience

Monitor
malfunctions on
& off

color

not good

Faint shadow
from the static
image displayed
appears on the
screen

Possible solutions

•Ensure that the video cable connecting the
monitor to the computer is connected properly
and is secure.

•Resetthemonitortofactorysettings.

•Perform monitor self-test feature check to

determine if the intermittent problem occurs in
self-test mode.

•Perform monitor self-test.

•Ensure that the video cable connecting the

monitor to the computer is connected properly
and is secure.

•Check for bent or broken pins in the video cable
connector.

•Change the settings of the Preset Modes
in the Color menu OSD depending on the
application.

•Adjust R/G/B value under Custom Color in
Color menu OSD.

•Change the Input Color Format to PC RGB or
YPbPr in the Color menu OSD.

•Run the built-in diagnostics.

•Use the Power Management feature to turn

o the monitor at all times when not in use
(for more information, see Power Management

Modes).

•Alternatively, use a dynamically changing
screensaver.

52 | Troubleshooting

Product specific problems

Problem What you

experience

Screen image is
too small

Cannot adjust
the monitor
with the
buttons on the
front panel

No Input Signal
when user
controls are
pressed

The picture
does not fill the
entire screen

Image is centered
on screen, but
does not fill entire
viewing area

OSD does not
appear on the
screen

No picture, the
LED light is white

The picture cannot
fill the height or
width of the screen

Possible solutions

•Check the Aspect Ratio setting in the
Display menu OSD.

•Reset the monitor to factory settings.

•Turn o the monitor, unplug the monitor

power cable, plug it back, and then turn on
the monitor.

•Check the signal source. Ensure the
computer is not in the power saving mode by
moving the mouse or pressing any key on the
keyboard.

•Check whether the signal cable is plugged
in properly. Connect the signal cable again, if
necessary.

•Reset the computer or video player.

•Due to dierent video formats (aspect ratio)

of DVDs, the monitor may display in full
screen.

•Run the built-in diagnostics.

Troubleshooting | 53

Appendix

FCC notices (U.S. only) and other regulatory information

For FCC notices and other regulatory information, see the regulatory compliance
website located at www.dell.com/regulatory_compliance.

Contacting Dell

For customers in the United States, call 800-WWW-DELL (800-999-3355).

NOTE: If you do not have an active Internet connection, you can find

contact information on your purchase invoice, packing slip, bill, or Dell
product catalog.

Dell provides several online and telephone-based support and service options.
Availability varies by country and product, and some services may not be
available in your area.

• Online technical assistance — www.dell.com/support/monitors

• Contacting Dell — www.dell.com/contactdell

54 | Appendix

Outline dimension

S2421H/HN/NX Outline Dimension

14.2

[0.56]

Unit : mm(inch)
Dimension : Nominal
Drawing : Not to scale

1.8

[0.07]

53.8

[2.12]

322.6

5.4
[0.21]

[12.70]

296.5

5.4

[11.67]

20.7

[0.21]

[0.82]

537.8
[21.17]

527.0
[20.75]

249.0
[9.80]

111.0

5.4
[0.21]

412.8

[4.37]

[16.25]

409.9

[16.14]

88.8

[3.50]

Tilt

Z=0

5

21

165.4
[6.51]

44.7
[1.76]

14.0

9.0

[0.36]

28.2
[1.11]

[0.55]

150.7

407.4

[5.93]

[16.04]

Z=34.7(1.37)

Z=43.0(1.69)

Z=44.0(1.73)(4x)

M4x10(4x)

79.9
[3.15]

15.0
[0.59]

152.8
[6.02]

100.0(2x)

[3.94]

159.4

[6.28]

122.0(2x)

[4.80]

171.6

[6.76]

S2721H/HN/NX Outline Dimension

1.8

6.0
[0.24]

363.6

6.0
[0.24]

[14.32]

336.3

14.3

6.0

[13.24]

21.3

[0.56]

[0.24]

[0.84]

609.9
[24.01]

597.9
[23.54]

257.2
[10.13]

111.0

[0.07]

[4.37]

54.0

453.3

[2.12]

[17.85]

450.0

[17.72]

88.2

[3.47]

Z=0

Tilt

5

21

9.0

[0.36]

42.5
[1.67]

60.7
[2.39]

191.7
[7.55]

Z=34.7(1.37)

Z=43.0(1.69)

Z=44.0(1.73) (4x)

445.4

[17.54]

155.1

[6.11]

15.1

[0.59]

Unit : mm(inch)
Dimension : Norminal
Drawing : Not to scale

M4x10(4x)

95.9
[3.78]

14.9
[0.59]

186.8
[7.35]

100.0(2x)

[3.94]

176.0

164.1

[6.46]

122.0(2x)

[4.80]

[6.93]